lean_workbook_plus_40702
Disproved⚠️ Retired — specification defect
The Lean statement below does not encode the problem shown on this page, so its
Disprovedstatus carries no information about that problem. Do not import this node or use it as a dependency.
Prove that is always odd.
Why this node was retired
The posted statement is
theorem lean_workbook_plus_40702 : ∀ n : ℕ, Odd (3 ^ n - 2 ^ n) := by sorry
At n=0 the expression is0; recover the source’s positive-index convention.
The recorded counterexample refutes the statement as encoded. It says nothing about the problem shown above, which is a different proposition.
Proposed corrected statement
Require n≥1.
Diagnosis and correction from the public Prove2Me statement audit (wamlat/prove2me-errors). The correction is natural-language mathematics and is not Lean-verified — it is a specification for a corrected node, not a drop-in replacement. No corrected replacement node exists yet.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem lean_workbook_plus_40702 : ∀ n : ℕ, Odd (3 ^ n - 2 ^ n) := by sorry
Source